diff --git a/Cargo.toml b/Cargo.toml
index e5d19f0dd2c5e3db8d304dc979408f8f9c2fba95..258a30287cfdafbbc1e850669b231fda1cbb8fe4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -41,7 +41,7 @@ lazy_static = "1.4.0"
 crate-type = ["cdylib"]
 
 [features]
-default = ["ffi", "session_optimization", "ffi_pseudo_socket_api"]
+default = ["ffi", "session_optimization"]
 ffi = [] # see src/ffi/mod.rs
 ffi_pseudo_socket_api = ["ffi", "libc", "os_socketaddr"]# see src/ffi/pseudo_socket_api.rs
 endpoint_logging = [] # see src/macros.rs
diff --git a/src/ffi/pseudo_socket_api.rs b/src/ffi/pseudo_socket_api.rs
index 254956b3749f660f6a2d9996d9fa43dc03fd457f..8d64015bcf1b3e0137e59ea38f415c0ce3c088d2 100644
--- a/src/ffi/pseudo_socket_api.rs
+++ b/src/ffi/pseudo_socket_api.rs
@@ -1,7 +1,7 @@
 use super::*;
 
-use libc::{sockaddr, socklen_t};
 use core::ops::DerefMut;
+use libc::{sockaddr, socklen_t};
 use std::{collections::HashMap, ffi::c_void, net::SocketAddr, os::raw::c_int, sync::RwLock};
 ///////////////////////////////////////////////////////////////////
 
@@ -14,6 +14,7 @@ enum ConnectorComplexPhased {
     Communication { putter: PortId, getter: PortId },
 }
 struct ConnectorComplex {
+    // invariant: .connector.phased and .phased are variants Setup/Communication in lockstep.
     connector: Connector,
     phased: ConnectorComplexPhased,
 }
@@ -33,10 +34,8 @@ unsafe fn libc_to_std_sockaddr(addr: *const sockaddr, addr_len: socklen_t) -> Op
 }
 impl Default for FdAllocator {
     fn default() -> Self {
-        Self {
-            next: Some(0), // positive values used only
-            freed: vec![],
-        }
+        // negative FDs aren't used s.t. they are available for error signalling
+        Self { next: Some(0), freed: vec![] }
     }
 }
 impl FdAllocator {
@@ -62,7 +61,8 @@ impl ConnectorComplex {
         match self.phased {
             ConnectorComplexPhased::Setup { local: Some(local), peer: Some(peer) } => {
                 // complete setup
-                let [putter, getter] = self.connector.new_udp_mediator_component(local, peer).unwrap();
+                let [putter, getter] =
+                    self.connector.new_udp_mediator_component(local, peer).unwrap();
                 self.connector.connect(None).unwrap();
                 self.phased = ConnectorComplexPhased::Communication { putter, getter }
             }
diff --git a/src/runtime/mod.rs b/src/runtime/mod.rs
index ee259424adb10d50f7f3b07dc3a4ffbd62bf878a..4ff25bc6eefbe4e62f889614e0892c06528cbde5 100644
--- a/src/runtime/mod.rs
+++ b/src/runtime/mod.rs
@@ -379,6 +379,17 @@ impl Drop for Connector {
     }
 }
 impl Connector {
+    pub fn is_connected(&self) -> bool {
+        // If designed for Rust usage, connectors would be exposed as an enum type from the start.
+        // consequently, this "phased" business would also include connector variants and this would
+        // get a lot closer to the connector impl. itself.
+        // Instead, the C-oriented implementation doesn't distinguish connector states as types,
+        // and distinguish them as enum variants instead
+        match self.phased {
+            ConnectorPhased::Setup(..) => false,
+            ConnectorPhased::Communication(..) => true,
+        }
+    }
     pub(crate) fn random_id() -> ConnectorId {
         type Bytes8 = [u8; std::mem::size_of::<ConnectorId>()];
         unsafe {